/* ====================================================================
   IKUUU - STYLE ㊷: BRUTALIST ARCHITECTURE
   Design Language: Architectural Brutalism / Raw Concrete / Structural Grid
   Visual Personality: 厚重、冷峻、力量感、建筑感
   Core Philosophy: Turn the website into a digital architectural structure.
   ==================================================================== */

:root {
  --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Brutalist Concrete & Industrial Palette */
  --bg-concrete-light: #f4f4f5;
  --bg-canvas: #eceeed;
  --bg-surface: #ffffff;
  --bg-dark: #09090b;
  --bg-charcoal: #18181b;
  --bg-steel: #e4e4e7;
  
  --text-primary: #09090b;
  --text-secondary: #27272a;
  --text-tertiary: #52525b;
  --text-inverse: #f4f4f5;
  
  /* Industrial Accent: Safety Orange / Alert Yellow */
  --accent-industrial: #ea580c;
  --accent-industrial-hover: #c2410c;
  --accent-yellow: #f59e0b;
  
  /* Structural Grid & Line Weights */
  --border-heavy: 2px solid #18181b;
  --border-structural: 1px solid #18181b;
  --border-light: 1px solid #d4d4d8;
  --border-concrete: 1px solid #a1a1aa;
  
  --max-width: 1200px;
  --content-width: 860px;
  --header-height: 72px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* 粗野主义原则：严禁圆角，纯粹几何直角 */
}

html {
  font-family: var(--font-stack);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-bottom: 76px;
  overflow-x: hidden;
  background-color: var(--bg-canvas);
}

@media (min-width: 769px) {
  body {
    padding-bottom: 0;
  }
}

a {
  color: var(--text-primary);
  text-decoration: none;
  transition: background-color 0.1s ease, color 0.1s ease;
}

a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent-industrial);
  outline-offset: 2px;
}

img, svg {
  vertical-align: middle;
  max-width: 100%;
}

ul, ol {
  list-style: none;
}

/* 结构化建筑容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.content-container {
  width: 100%;
  max-width: var(--content-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 工业粗野主义按钮：矩形、强边界、整块颜色反转 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.5px;
  cursor: pointer;
  text-decoration: none !important;
  line-height: 1;
  border: var(--border-heavy);
  white-space: nowrap;
  transition: transform 0.1s ease, background-color 0.1s ease, color 0.1s ease;
  text-transform: uppercase;
}

/* 主 CTA：工业安全橙 (Safety Orange) / 悬停反转为黑底白字 */
.btn-primary {
  background-color: var(--accent-industrial);
  color: #ffffff !important;
  border-color: var(--bg-charcoal);
  box-shadow: 3px 3px 0px var(--bg-charcoal);
}

.btn-primary:hover {
  background-color: var(--bg-charcoal);
  color: #ffffff !important;
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0px var(--accent-industrial);
}

.btn-primary:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0px var(--bg-charcoal);
}

/* 次级按钮：混凝土灰底 / 悬停反转为纯黑 */
.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-primary) !important;
  border-color: var(--bg-charcoal);
  box-shadow: 3px 3px 0px var(--bg-charcoal);
}

.btn-secondary:hover {
  background-color: var(--bg-charcoal);
  color: #ffffff !important;
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0px var(--text-tertiary);
}

.btn-lg {
  min-height: 54px;
  padding: 16px 36px;
  font-size: 17px;
  font-weight: 800;
}

.btn-block {
  display: flex;
  width: 100%;
}

/* 顶部导航：混凝土立面梁架构 */
.site-header {
  height: var(--header-height);
  background-color: var(--bg-surface);
  border-bottom: var(--border-heavy);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.site-logo {
  font-size: 24px;
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none !important;
  min-height: 48px;
}

.site-logo svg {
  color: var(--accent-industrial);
}

.site-logo span {
  font-family: var(--font-stack);
  font-weight: 900;
  color: var(--text-primary);
}

.site-logo .logo-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  background-color: var(--bg-charcoal);
  color: #ffffff;
  padding: 2px 6px;
  letter-spacing: 1px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  border: 1px solid transparent;
  transition: all 0.1s ease;
}

.nav-link:hover {
  background-color: var(--bg-steel);
  border-color: var(--bg-charcoal);
  text-decoration: none;
}

.header-cta {
  display: flex;
  align-items: center;
}

/* 汉堡按钮 */
.menu-toggle {
  display: none;
  background: var(--bg-surface);
  border: var(--border-heavy);
  color: var(--text-primary);
  width: 48px;
  height: 48px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

@media (max-width: 768px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--bg-surface);
    border-bottom: var(--border-heavy);
    flex-direction: column;
    padding: 16px 20px;
    gap: 8px;
  }

  .site-nav.nav-open {
    display: flex;
  }

  .site-nav .nav-link {
    width: 100%;
    padding: 12px 16px;
    border: var(--border-structural);
    background-color: var(--bg-concrete-light);
  }
}

/* ====================================================================
   HERO 区域: 巨型标题 + 建筑结构美学
   ==================================================================== */
.hero-section {
  padding: 72px 0 60px;
  background-color: var(--bg-surface);
  border-bottom: var(--border-heavy);
  position: relative;
}

/* 顶部工业参数标注 */
.hero-meta-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
  padding-bottom: 24px;
  border-bottom: var(--border-structural);
  margin-bottom: 40px;
  text-transform: uppercase;
}

.hero-meta-top span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.hero-meta-top .status-indicator {
  width: 8px;
  height: 8px;
  background-color: var(--accent-industrial);
  display: inline-block;
}

/* 巨型 Monumental 标题：占据视野，冲击力强 */
.hero-title {
  font-size: 52px;
  font-weight: 900;
  line-height: 1.15;
  color: var(--text-primary);
  margin-bottom: 24px;
  letter-spacing: -1.5px;
  text-transform: uppercase;
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 500;
  color: var(--text-secondary);
  max-width: 820px;
  margin-bottom: 36px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 48px;
}

/* 建筑线框图视觉区域 (Architectural Wireframe Grid) */
.hero-blueprint {
  background-color: var(--bg-concrete-light);
  border: var(--border-heavy);
  padding: 28px 24px;
  margin-bottom: 40px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
}

.blueprint-info h3 {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent-industrial);
  margin-bottom: 6px;
  letter-spacing: 1px;
}

.blueprint-info p {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
}

.blueprint-diagram {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* 底部信任矩阵 */
.hero-trust-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: var(--border-structural);
  background-color: var(--bg-concrete-light);
}

.trust-item {
  padding: 16px 20px;
  border-right: var(--border-structural);
  font-size: 13px;
  font-weight: 700;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.trust-item:last-child {
  border-right: none;
}

.trust-item svg {
  color: var(--accent-industrial);
  flex-shrink: 0;
}

@media (max-width: 860px) {
  .hero-title {
    font-size: 34px;
    letter-spacing: -0.5px;
  }
  .hero-subtitle {
    font-size: 16px;
  }
  .hero-blueprint {
    grid-template-columns: 1fr;
  }
  .hero-trust-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .trust-item:nth-child(2) {
    border-right: none;
  }
  .trust-item:nth-child(3) {
    border-top: var(--border-structural);
  }
  .trust-item:nth-child(4) {
    border-top: var(--border-structural);
    border-right: none;
  }
}

@media (max-width: 640px) {
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .hero-trust-grid {
    grid-template-columns: 1fr;
  }
  .trust-item {
    border-right: none;
    border-bottom: var(--border-structural);
  }
  .trust-item:last-child {
    border-bottom: none;
  }
}

/* ====================================================================
   通用 Section 架构：结构分明、冷峻高对比
   ==================================================================== */
.section {
  padding: 80px 0;
  border-bottom: var(--border-heavy);
}

.section-alt {
  background-color: var(--bg-surface);
}

.section-header {
  margin-bottom: 48px;
  position: relative;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 800;
  color: var(--accent-industrial);
  letter-spacing: 1.5px;
  display: inline-block;
  margin-bottom: 8px;
  text-transform: uppercase;
}

.section-title {
  font-size: 34px;
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  line-height: 1.2;
  text-transform: uppercase;
}

.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 720px;
  margin-top: 10px;
}

/* ====================================================================
   1. 核心优势 (Benefits) - 建筑三栏结构块
   ==================================================================== */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: var(--border-heavy);
  background-color: var(--bg-charcoal);
  gap: 2px; /* 形成 2px 黑色分割线 */
}

.benefit-card {
  background-color: var(--bg-surface);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.benefit-num {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 900;
  color: var(--bg-steel);
  line-height: 1;
  margin-bottom: 16px;
}

.benefit-tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  color: var(--bg-charcoal);
  background-color: var(--bg-steel);
  padding: 4px 10px;
  margin-bottom: 14px;
  text-transform: uppercase;
  border: 1px solid var(--border-concrete);
}

.benefit-card h3 {
  font-size: 20px;
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 14px;
  line-height: 1.3;
}

.benefit-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.65;
}

@media (max-width: 860px) {
  .benefits-grid {
    grid-template-columns: 1fr;
  }
}

/* ====================================================================
   2. 特性网格 (Features 4 cards) - 结构四分区
   ==================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border: var(--border-heavy);
  background-color: var(--bg-charcoal);
  gap: 2px;
}

.feature-card {
  background-color: var(--bg-surface);
  padding: 36px 32px;
  display: flex;
  flex-direction: column;
}

.feature-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  border-bottom: var(--border-structural);
  padding-bottom: 14px;
}

.feature-code {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 800;
  color: var(--accent-industrial);
}

.feature-icon-box {
  width: 44px;
  height: 44px;
  background-color: var(--bg-dark);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-content h3 {
  font-size: 19px;
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.feature-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}

/* ====================================================================
   3 & 4. 支持矩阵 (Streaming & AI) - 工业铭牌 Blocks
   ==================================================================== */
.support-matrix {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: var(--border-heavy);
  background-color: var(--bg-charcoal);
  gap: 1px;
}

.support-pill {
  background-color: var(--bg-surface);
  padding: 18px 24px;
  font-size: 14px;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
  border: none;
}

.support-pill svg {
  color: var(--accent-industrial);
  flex-shrink: 0;
}

@media (max-width: 768px) {
  .support-matrix {
    grid-template-columns: 1fr;
  }
}

/* ====================================================================
   5. 使用场景卡片 (Use Cases 3 cards) - 建筑空间模块
   ==================================================================== */
.use-cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.scenario-card {
  background-color: var(--bg-surface);
  border: var(--border-heavy);
  padding: 32px 26px;
  display: flex;
  flex-direction: column;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
}

.scenario-header {
  border-bottom: var(--border-structural);
  padding-bottom: 16px;
  margin-bottom: 16px;
}

.scenario-zone {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 800;
  color: var(--accent-industrial);
  letter-spacing: 1px;
  display: block;
  margin-bottom: 6px;
}

.scenario-title {
  font-size: 19px;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1.3;
}

.scenario-device {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
  background-color: var(--bg-steel);
  padding: 4px 8px;
  display: inline-block;
  margin-top: 10px;
}

.scenario-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
  flex-grow: 1;
}

@media (max-width: 860px) {
  .use-cases-grid {
    grid-template-columns: 1fr;
  }
}

/* ====================================================================
   6. 定价卡 (Pricing 3 tiers) - 建筑结构式比较立面
   ==================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background-color: var(--bg-surface);
  border: var(--border-heavy);
  padding: 40px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
}

/* 推荐档位：工业橙强调边框 + 实心黑底铭牌 */
.pricing-card.featured {
  border: 3px solid var(--accent-industrial);
  box-shadow: 6px 6px 0px var(--bg-charcoal);
  transform: translateY(-4px);
}

.pricing-badge {
  position: absolute;
  top: -16px;
  left: 30px;
  background-color: var(--accent-industrial);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 900;
  padding: 4px 14px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.pricing-name {
  font-size: 22px;
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.pricing-audience {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 24px;
  line-height: 1.5;
  min-height: 38px;
}

.pricing-price {
  border-top: var(--border-structural);
  border-bottom: var(--border-structural);
  padding: 20px 0;
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 22px;
  font-weight: 900;
  color: var(--text-primary);
}

.price-number {
  font-size: 52px;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1;
  font-family: var(--font-mono);
}

.price-period {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.pricing-features {
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features li svg {
  color: var(--accent-industrial);
  flex-shrink: 0;
}

@media (max-width: 860px) {
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .pricing-card.featured {
    transform: none;
  }
}

/* ====================================================================
   7. 常见问题 (FAQ 6 题) - 原生 details 手风琴
   ==================================================================== */
.faq-list {
  max-width: 900px;
  margin: 0 auto;
  border: var(--border-heavy);
  background-color: var(--bg-charcoal);
}

.faq-item {
  background-color: var(--bg-surface);
  border-bottom: var(--border-heavy);
  overflow: hidden;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  font-size: 17px;
  font-weight: 800;
  color: var(--text-primary);
  padding: 22px 28px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  min-height: 52px;
  transition: background-color 0.1s ease;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question:hover {
  background-color: var(--bg-concrete-light);
}

.faq-chevron {
  width: 20px;
  height: 20px;
  color: var(--text-primary);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.faq-item[open] .faq-question {
  background-color: var(--bg-concrete-light);
  border-bottom: var(--border-structural);
}

.faq-item[open] .faq-chevron {
  transform: rotate(180deg);
  color: var(--accent-industrial);
}

.faq-answer {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  padding: 22px 28px;
  background-color: var(--bg-surface);
}

/* ====================================================================
   8. 最终 CTA 区域 - 巨型建筑门楼感
   ==================================================================== */
.final-cta {
  background-color: var(--bg-dark);
  color: #ffffff;
  padding: 80px 0;
  text-align: center;
  border-bottom: var(--border-heavy);
  position: relative;
}

.final-cta h2 {
  font-size: 38px;
  font-weight: 900;
  margin-bottom: 16px;
  color: #ffffff;
  letter-spacing: -0.5px;
  text-transform: uppercase;
}

.final-cta p {
  font-size: 18px;
  color: #a1a1aa;
  max-width: 680px;
  margin: 0 auto 36px;
  line-height: 1.6;
}

.final-cta .btn-cta-white {
  background-color: var(--accent-industrial);
  color: #ffffff !important;
  border-color: #ffffff;
  box-shadow: 4px 4px 0px #ffffff;
  font-size: 18px;
  font-weight: 900;
}

.final-cta .btn-cta-white:hover {
  background-color: #ffffff;
  color: var(--bg-dark) !important;
  box-shadow: 4px 4px 0px var(--accent-industrial);
}

/* ====================================================================
   移动端吸底 CTA 栏
   ==================================================================== */
.mobile-sticky-bar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-surface);
  border-top: var(--border-heavy);
  padding: 12px 20px;
  z-index: 999;
  transform: translateY(100%);
  transition: transform 0.25s ease;
}

.mobile-sticky-bar.bar-visible {
  transform: translateY(0);
}

.mobile-sticky-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.mobile-sticky-info {
  font-size: 14px;
  font-weight: 800;
  color: var(--text-primary);
}

.mobile-sticky-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-tertiary);
}

@media (max-width: 768px) {
  .mobile-sticky-bar {
    display: block;
  }
}

/* ====================================================================
   页脚区域: 纯粹结构排版，严谨克制
   ==================================================================== */
.site-footer {
  background-color: var(--bg-surface);
  border-top: var(--border-heavy);
  padding: 48px 0 36px;
  font-size: 14px;
  color: var(--text-secondary);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  align-items: center;
  border-bottom: var(--border-structural);
  padding-bottom: 20px;
}

.footer-nav a {
  font-size: 14px;
  font-weight: 800;
  color: var(--text-primary);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  text-transform: uppercase;
}

.footer-nav a:hover {
  color: var(--accent-industrial);
  text-decoration: underline;
}

.footer-disclosure {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  padding: 16px 20px;
  background-color: var(--bg-concrete-light);
  border: var(--border-structural);
  line-height: 1.6;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ====================================================================
   内页与文章排版通用 (Editorial Brutalism)
   ==================================================================== */
.page-header {
  background-color: var(--bg-surface);
  border-bottom: var(--border-heavy);
  padding: 48px 0;
  margin-bottom: 40px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
  margin-bottom: 16px;
  text-transform: uppercase;
}

.breadcrumb a {
  color: var(--text-tertiary);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.breadcrumb a:hover {
  color: var(--accent-industrial);
}

.page-title {
  font-size: 36px;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
  text-transform: uppercase;
}

.article-content {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
}

.article-content h2 {
  font-size: 24px;
  font-weight: 900;
  color: var(--text-primary);
  margin: 44px 0 18px;
  padding-bottom: 10px;
  border-bottom: var(--border-heavy);
  letter-spacing: -0.5px;
}

.article-content h3 {
  font-size: 19px;
  font-weight: 800;
  color: var(--text-primary);
  margin: 28px 0 14px;
}

.article-content p {
  margin-bottom: 20px;
}

.article-content ul, .article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-content ul {
  list-style: square;
}

.article-content ol {
  list-style: decimal;
}

.article-content li {
  margin-bottom: 10px;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 14px;
  border: var(--border-heavy);
}

.article-content th, .article-content td {
  border: var(--border-structural);
  padding: 12px 16px;
  text-align: left;
}

.article-content th {
  background-color: var(--bg-charcoal);
  color: #ffffff;
  font-weight: 800;
  font-family: var(--font-mono);
  text-transform: uppercase;
}

.article-content td {
  background-color: var(--bg-surface);
}

.article-faq-box {
  background-color: var(--bg-surface);
  border: var(--border-heavy);
  padding: 32px;
  margin: 40px 0;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
}

.article-faq-box h3 {
  margin-top: 0;
  margin-bottom: 18px;
  font-size: 20px;
  font-weight: 900;
  border-bottom: var(--border-structural);
  padding-bottom: 12px;
}

.article-end-cta {
  background-color: var(--bg-dark);
  color: #ffffff;
  border: var(--border-heavy);
  padding: 36px 30px;
  text-align: center;
  margin: 48px 0;
  box-shadow: 6px 6px 0px var(--accent-industrial);
}

.article-end-cta h2, .article-end-cta h3 {
  font-size: 24px;
  font-weight: 900;
  color: #ffffff;
  margin-bottom: 10px;
  letter-spacing: -0.5px;
}

.article-end-cta p {
  font-size: 15px;
  color: #a1a1aa;
  margin-bottom: 22px;
}

.related-articles {
  border-top: var(--border-heavy);
  padding-top: 32px;
  margin-top: 48px;
}

.related-articles h3 {
  font-size: 20px;
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 18px;
}

.related-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.related-item {
  background-color: var(--bg-surface);
  border: var(--border-structural);
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color 0.1s ease;
}

.related-item:hover {
  background-color: var(--bg-concrete-light);
  border-color: var(--bg-charcoal);
}

.related-item a {
  font-weight: 800;
  color: var(--text-primary);
}

/* 指南页卡片 */
.guides-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-bottom: 54px;
}

.guide-summary-card {
  background-color: var(--bg-surface);
  border: var(--border-heavy);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
  transition: transform 0.1s ease;
}

.guide-summary-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0px var(--accent-industrial);
}

.guide-card-icon {
  margin-bottom: 18px;
  width: 44px;
  height: 44px;
  background-color: var(--bg-charcoal);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.guide-summary-card h3 {
  font-size: 20px;
  font-weight: 900;
  margin-bottom: 12px;
}

.guide-summary-card h3 a {
  color: var(--text-primary);
}

.guide-summary-card h3 a:hover {
  color: var(--accent-industrial);
}

.guide-summary-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 20px;
  flex-grow: 1;
  line-height: 1.65;
}

.guide-card-meta {
  display: flex;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--text-tertiary);
  margin-bottom: 14px;
  text-transform: uppercase;
}

.guide-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  border-top: var(--border-structural);
  padding-top: 14px;
}

.guide-card-footer a {
  font-family: var(--font-mono);
  font-weight: 800;
  color: var(--accent-industrial);
  text-transform: uppercase;
}

@media (max-width: 768px) {
  .guides-grid {
    grid-template-columns: 1fr;
  }
}

/* 网站地图 */
.sitemap-section {
  background-color: var(--bg-surface);
  border: var(--border-heavy);
  padding: 30px;
  margin-bottom: 28px;
  box-shadow: 4px 4px 0px var(--bg-charcoal);
}

.sitemap-section h2 {
  font-size: 20px;
  font-weight: 900;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: var(--border-heavy);
}

.sitemap-list li {
  margin-bottom: 12px;
  font-size: 15px;
}

.sitemap-list a {
  font-weight: 700;
}

/* 减弱动画支持 */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}